As more and more people come forward with accounts of near-death experiences, new research is about to examine the out of body experience to see whether mind and body really do separate at the point of death.

It is only 30 years ago that the term near-death experience was coined. An American researcher, Raymond Moody, used it to describe the reports of a large number of people who, whilst apparently dead, had seen deceased relatives, tunnels of light, life reviews and felt an overwhelming sense of peace, before being resuscitated.

Recent studies have shown that one in 10 people who have had a cardiac arrest report an near-death experience (NDE). These experiences are reported across many cultures and religions. Some believe they offer a glimpse of an afterlife while others see them as the result of a dying brain.

In March Dr Sam Parnia and Professor Peter Fenwick will begin a year-long study, looking at patients who have had cardiac arrests to find out if they have had any experiences or memories whilst their heart stopped beating.

It seems to me many of the ingredients of a belief in heaven are present in the near-death experience and confirmed by it

Professor Paul Badham

In particular they are interested in those who report an out-of-body experience (OBE), when the "experiencer" looks down on their body and surroundings from a height.

At Hammersmith Hospital and 12 other hospitals across the UK, symbols will be placed in strategic places so that only those who have an OBE will be able to see them.

"If these claims are verified" says Dr Sam Parnia, "then this will have a huge implication for science because what it would indicate for us is that our current understanding of mind, body and brain isn't sufficient and that it is possible for the mind/consciousness to separate from the brain at the end of life."

However, a similar but small scale study at Morriston Hospital, Swansea, last year was inconclusive. Over a five-year period eight out of 39 cardiac arrest patients had a NDE and of those only two had an OBE. Unfortunately, neither of them was in the right place to spot the symbols.

Evidence of the 'other side'

Penny Sartori, who conducted the research at Morriston Hospital, believes it is very easy for people to dismiss NDE as hallucinations.

NDEs are described as beatific visions

"I documented 12 cases of people who had had hallucinations and I found that the hallucinations were very different from the NDE." Hallucinations tend to be random and non-specific whereas the NDEs follow a definite pattern and the reports are very clear and precise.

Professor Paul Badham, from the University of Wales, Lampeter, who helped oversee this study, believes these experiences are evidential for believing in heaven.

"People do describe a paradise or kind of environment, they do describe being met by a being of light who seems to know them, they often have a review of their past life. They often have a sense of passing self judgement on that kind of life that they have lived. So it does seem to me that many of the ingredients of a belief in heaven are present in the NDE and confirmed by it."

However, Professor Christopher French, who looks into paranormal experiences at Goldsmith College, London, is more sceptical. "Virtually all the aspects of the NDE have been reported in other contexts," he says.

THE NEW STUDY

13 hospitals taking part

Symbols to be placed in strategic places

Will only be seen by those having an out-of-body experience

The life review can be caused by the brain firing in unusual ways as a result of a lack of oxygen or too much carbon dioxide in the blood stream. Endorphins released during times of stress can create a sense of peace and the tunnel of light could reflect abnormal patterns of firing in the visual cortex.

"I think it will be a long time before we fully understand the NDE," says Professor French, "but it's an incredibly fascinating and profound experience for the people that have it and it would certainly be a mistake for science to close its eyes towards those kinds of experience.

"Potentially they can tell us an awful lot, not only about how the brain may operate at the kind of extremes but also about normal everyday consciousness and so, definitely, we ought to carry on studying these experiences and taking them seriously."

After Death, What? will be broadcast in the UK on BBC Radio 4 at 2030 GMT on Monday 26, January.